Question Discussion & Solution

Concept:

Indian Space Research Organisation (ISRO):

• It is the premier space agency of the government of India.
• Its vision is to harness space technology for national development while pursuing space science research and planetary exploration.
• The space research activities were initiated in India under Dr. Vikram Sarabhai, the founding father of the Indian space program, during the 1960s.
• ISRO established: 15 August 1969
• Headquarters: Bengaluru

​Explanation:

Vikram Sarabhai:

• Vikram Sarabhai was an Indian Physicist.
• He Initiated Space Research.
• He is also known as the 'Father of the Indian space program'.
• Vikram Sarabhai also researched cosmic Rays under Dr. C.V. Raman, a noble prize winner.

Thus, the Indian Space Research Center was formed by Vikram Sarabhai.

Additional Information 

Homi Baba:

• Homi Baba worked towards the development of nuclear power.
• Known as the 'Father of the Indian nuclear program'
• He founded the Tata Institute Of Fundamental Research. 

Rakesh Sharma:

• Rakesh Sharma is the first Indian citizen to travel to space.
• Rakesh Sharma flew aboard Soyuz T - 11 along with Yury Malyshev and Flight Engineer Gennadi Strekalov.
• He became the first Indian to enter space in 1984.
• He was an officer in the Indian Air Force.
• He was awarded the honour of “the Hero of the Soviet Union”.
• He also received Ashok Chakra, India’s highest peacetime gallantry award.

K Sivan:

• Dr K Sivan was the Chairman of Indian Space Research Organisation uptill 2021.
• He was born in 1957 in Kanyakumari, Tamil Nadu.
• Dr Sivan was inducted into Polar Satellite Launch Vehicle Project of ISRO in 1982.
• He also served as Director at Liquid Propulsion Systems Centre at ISRO and Vikram Sarabhai Space Centre.
• He assumed the office as chief of ISRO in 2018.

CONCEPT:​

• Power of Lens: The inverse of the focal length is known as the power of the lens.
  • It shows the bending strength for the light ray of the lens.

\(P = \frac{1}{f}\)

where P is the power of the lens and f is the focal length of the lens.

• The unit of power of a lens is Dioptre when the focal length of the lens is taken in meter (m).
• The focal length of the convex lens (converging) is positive and that of the concave lens (diverging) is negative. 

CALCULATION:

Given that lens is diverging. so focal length is negative.

f = -5 cm = -0.05 m

Power of lens \(P = \frac{1}{f} =\frac{1}{-0.05} = -20 D\)

P = -20 D

So the correct answer is option 2.

The correct answer is option 1.

Concept:

Weak entity set :

A weak entity set is an entity set that does not contain sufficient attributes to uniquely identify its entities. In other words, a primary key does not exist for a weak entity set. However, it contains a partial key called a discriminator. Discriminators can identify a group of entities from the entity set.

ER diagram:

This ER diagram illustrates key information about the book, including entities such as author, Publisher, books, and Edition. It allows for understanding the relationships between entities.

Author:

For an author, the book dealer might want to keep track of the name (first, middle, and last), date of birth, and date of death.​

Publisher: 

For a Publisher, the book dealer might want to keep track of the phone, name, and address.

Book:

For a book, the book dealer might want to keep track of the id, title, and date.

Edition:

For an edition, the book dealer might want to keep track of the name and the total number of copies.

Relation ER diagram,

• The author can write a number of books and each number of books has many numbers of authors. So it has many to many relationships.
• The book can publish at most one publisher and each number of publishers has many numbers books. So it has many to one relationship.
• The book can has atmost one edition and each number edition has many numbers of books. So it has many to one relationship.

The ER diagram,

Here Edition is a weak entity because it can not have candidate key attributes.​

Hence the correct answer is Edition.

The correct option is Most of the bees in the hive are worker bees.

• Every honey bee colony comprises a single queen, a few hundred drones and several thousand worker castes of honey bees.
• A queen bee is the only female bee in the hive that gets to reproduce.
• Worker bees are all female and are all offspring of the queen. 
• Queen is a fertile, functional female, the worker is a sterile female and the drone is a male insect.
• Queen and worker develop from the fertilized egg while drone develops from an unfertilized egg.
• Further differentiation of queen and worker depends on the quality and quantity of food that is fed to the queen or worker larvae.

Explanation:

​Every beehive has one male bee and many female bees → Inorrect.

Most of the bees in the hive are worker bees → Correct

The study of honey bee is sericulture → Inorrect.

Beehives are octagonal in shapes→ Incorrect. (Hexagonal)

​Additional Information

The queen:

• ​There is only one queen in a colony and considerably larger than the members of other castes.
• Swarming is the natural method that honeybee colonies use for multiplying their colonies.
• The old queen is killed as soon as the new queen is fertilized.
• The phenomenon of raising a queen in the off-season is called supersedure.
• The normal lifespan of a queen is 3 years.

​The drone:

• ​The drones are male bees with no sting.
• They are much larger and stouter than either the queen or the workers.
• Their only function is to impregnate the young queen a task which they are unable to perform until they are about 10 days of age.
• They also help in the maintenance of hive temperature. 
• The drones are produced by unfertilized eggs of the queen, or by those workers which take up the reproductive function due to the absence of a queen in a colony.
• The normal lifespan of a drone is 57 days. 

​The worker:

• ​Smallest inhabitants of the beehive.
• They are imperfect females incapable of laying eggs.
• Worker bees primary duties are cleaning, feeding developing larva once hypopharyngeal glands develop, ripening of honey, secreting/moulding of wax into combs.
• The lifespan of a worker is about 4 weeks during the active season and 8 to 10 weeks during the less active season.
• On certain occasions when the colony is in need of a queen, some of the workers start laying eggs from which only drones are produced.
• These workers called laying workers.

The pattern followed here is:

Hence, 119 is the next term in the series.